I never pay attention to the absolute time, but when they need a charge they make a sound to indicate it and then you can easily put one in the case/charger and then put it back in your ear when it’s charged and then charge the other one, all without pausing your call. This duty cycling means you are effectively limited by the case battery size not the bud battery size.

I agree with the others upthread that I’m not going back to wires after getting my AirPods.